Nested if

A nested if is an if statement inside another if or else block. It allows checking multiple conditions at different levels.

Example:

int age = 25;
boolean hasLicense = true;

if (age >= 18) {
    System.out.println("Adult");
    if (hasLicense) {
        System.out.println("Can drive");
    } else {
        System.out.println("Cannot drive");
    }
} else {
    System.out.println("Minor");
}

Nested if‑else if:

int x = 10, y = 20;

if (x > 0) {
    if (y > 0) {
        System.out.println("Both positive");
    } else {
        System.out.println("x positive, y non‑positive");
    }
} else {
    System.out.println("x non‑positive");
}

Best practices:

• Avoid deep nesting (more than 2‑3 levels) for readability.
• Consider extracting inner conditions into separate methods or using logical operators (&&, ||).

// Instead of deep nesting:
if (x > 0 && y > 0) {
    System.out.println("Both positive");
}